After testing is complete, participants will then be given a dose of antihistamine (Zyrtec) and topical calamine lotion to pin prick areas to decrease irritation. There will be careful monitoring for extreme hypersensitivity or anaphylaxis as is the usual standard of care when testing children for allergies. However, classic systemic allergic reactions are caused by protein allergens. As histamine and codeine are not protein compounds, a systemic allergic reaction would not be expected. An epinephrine pen will be on hand for use if such an unusual reaction occurs.